Internal combustion engine



March 5, 1940- s. K. HOFFMAN INTERNAL COMBUSTION ENGINE F'iled'Nov. 5,1934 s Sheets-Sheet 1 March 5, 1940. s HOFFMAN 2,192,442

II I'lERNAL COMBUSTION ENGINE Filed Nov. 5, 1934 3 Sheets-Sheet 2Patented Mar. 5, i940 UNITE mm OFFICE INTERNAL COMBUST IGN ENGINE SamuelK. Hoffman, Willianisport, Pa, assignor,

by means assignments, to Aviation niacturlng Corporation, Chicago, lit,a corporation of Delaware Application November 5, 19341, vtierialirio.751,491 l 2 Claims.

ment which includes a lubricant pump and an impeller for the coolantwhich, in starting, are adapted to be operated independently of thecrank-shaft and pistons and other operating parts of the auin'liaryequipment, so that the lubricant and fluid which is normally used forcooling may be pre-heated to circulate heated fluid to increase thetemperature of the working parts of the engine and aid combustion andheat' ed oil to reduce friction in the working parts preparatory ,to,and for facilitating the starting of the engine.

Other objects of the invention will appear from the detaileddescription.

The invention consists in the several novel features'hereinafter setforth and more particularly defined by claims at the conclusion hereof.In the drawings: Fig. 1 is a longitudinal section of a portion of aninternal combustion engine having the invention applied thereto. Fig. 2is a transverse section taken on line 2-2 of Fig. 1. Fig. 31s a sectionon an enlarged scale taken on line 3-3 of Fig. 2, illustrating thereversible shaft between the engine and the auxiliary assembly and theover-running clutch for driving the lubricant pump and impeller forcooling fluid and the driving mechanism therefor. Fig. 4 is an elevationof the reversible drive-shaft for the auxiliary equipment positioned soit will drive the auxiliary equipment in the same direction as shown inFig. 3 froman' oppositely rotating engine.

The invention is exemplified in an engine comprising a casing orcrank-case 20; a crank-shaft 23 which is journaled in the crank-case at2|! and such other usual elementsof an internal combustion engine, allof which may be of any suitable construction, as well understood in theart. The auxiliary equipment of the engine comprises a rotary pump B forsupercharging the engine; an electric starter C connectable to initiallydrive the crank-shaft; a rotary pump D.

for forcing the .air or cooling fluid to the cooling means for theengine; a fuel-charging pump E and a pump G for circulating lubricantthrough the lubricating system of the engine, all of which are of theuni-directional rotary type or connected to the engine so that each willfunction J by rotation in a single direction. The crank-case 5 is formedof vertically divided sections. The auxiliary equipment is driven fromone end of. the

crank-shaft 23. The driving mechanism for the auxiliary equipment iscarried in a rearward extension 26 of the crank-case 20 and a sectionalIll casing or housing which is carried by the enginecase and comprises ahead 24 and a housing 21, both of which are removably secured to therear end of the extension 26.

The mechanism for driving the auxiliary equipment comprises a hollowshaft 28 which is reversible from. end to end and is provided withsplines 36 adjacent, but spaced from, one of its ends and splines 36 atits other end; an axially extending socket 29 in the outer end of thecrank- 10 shaft 23 which is provided with elongated splines 29 which areadapted to interflt with either of the splines 30, 30 according to theposition of the shaft 28; a bevel-gear 33 which is provided with anintegral hollow shaft 3! carried in a 33 ball-bearing 32 and with a hub34 which is jour-' naled 'in the spider 35, and is provided with splines31 which are adapted to be driven by splines 30 on shaft 28; a matingbevel-gear 38 which is coaxial with gear 33 and provided with 0 I a hubwhich is journaled in spider 36; and a set ,of intermediate gears 40', 4I, 42, which mesh constantly with both of the gears 33, 36. Gears 46,4|, 42 transmit power between gears 33, 36 and are, respectively,adapted to drive in the same 35 direction the elements of theuni-directional auxiliary equipment from a crank-shaft which is driveneither in one or the opposite direction.

Shaft 28 is reversible from end to end to drive either of the rotatablegears 33, 36, which are m driven in relatively opposite directionsthrough gears 46, il and 42, in the same direction as the crank-shaft orengine. I For this purpose, when shaft 28 is in one position (Fig. 3),splines 30 on shaft 28 interfit with the splines 29 and splines 5 30 onshaft 28 interfit with splines 31 on gear 33 and drive the gear 33 inthe same direction as the crank-shaft when shaft 28 is in one of itsalternative positions. In the reversed position v(F'ig. 4) of shaft 23,splines 30 will interfit with the inner ends of the splines 29* in thecrank- V shaft and splines 30 on shaft 28 will interfit with splines 31on gear 36 and drive the gear 36 in the same direction as thecrank-shaft 23. The rotary auxiliary equipment is usually adapted foroperation in one direction only. When the shaft 28 is coupled, forexample, to the crank-shaft of an engine with right-hand rotation, andto gear 33, as shown in Fig. 3, gear 33 will drive the gears All, 4|, 62in the correct direction for operating the rotary auxiliary equipment.When the equipment is to be used with an engine or crank-shaft withleft-hand rotation, the shaft 28 is reversed (Fig. 4) to positionsplines on shaft 28 where they will interfit with the inner ends ofsplines 29 and splines 30 on shaft a will interfit with the splines 3'!on gear 26. As a result, gear 36 will be driven in the same direction asthe crank-shaft and the auxiliary equipment will be driven in the samedirection as it is driven by gear 33 when the latter is operated from anoppositely rotating engine. This feature adapts the auxiliary equipmentfor selective functioning with either a left or right-hand engine. Theaxes of the three beveled intermediate gears 46, 4| and 42 are radialfrom the axis of the gears 33, 36 to provide compact mechanism fordriving the auxiliary equipment.

Beveled intermediate gear 46 is provided with an integral shaft 43 whichis mounted in a sectional head 44 which is removably secured in theextension 26 of the crank-case 20 and is adapted to be driven by anelectric starter C which may be of any suitable construction. A ratchetclutch 46 is provided on the outer end of. shaft 43 and is adapted to bedriven by co-axial clutch wheel 41 on the starter. Clutch wheel 41 isadapted to be automatically coupled with clutch wheel 46 when thestarter is operated to start the motor, as well understood in the art.

When reversible shaft 28 is connected to drive gear 33, the starter,through gear 40, will drive the crank-shaft in one directiomand whenshaft 28 is coupled to gear 36, the direction of rotation of thecrank-shaft by gear will be in'the opposite direction. As a result, thestarter mechanism is adapted to drivethe crank-shaft to start the engineaccording to the selected direction of rotation of the engine and by thereversal of shaft 28.

Beveled intermediate gear 4|, which meshes with beveled gears 33, 36, ismounted in a sectional head 48 which is removably secured inhousing-member 21 and is provided with an integral shaft 5|].- A pinion5| is splined to the outer end of shaft 5|) and meshes with an internalgear 52 on the shaft 53 of the fuel-charging pump E which is removablysecured against the outerend of the head 48 and with said head tohousing-member 21. The fuel-charging pump 54 is of the rotary type andmay be of any suitable,

construction, as well understood in the art.

Beveled gear 42, which also meshes with oppositely rotating, beveledgears 33, 36, has an integral shaft 58, which is journaled in asectional head 59, which is mounted in the cylindrical member of thecasing extension 26. Shaft 58 is connected to drive a co-axial shaft 6|also mounted in head 59 through an over-running or one-Way spring clutch62 mounted in cylindrical recesses in the contiguous ends of saidshafts, so'as to per-- mit shaft 6| to be driven in one directionindependently of the shaft 58, intermediate gears 40, 4|, 42 and thegears 33, 36.

A shaft 63 for operating the coolant pump D and co-axial with shafts 6|and 58, is journaled ina head 64 which is removably secured to a memberof the case-extension 26, and has its upper end splined to shaft 6|. Thepump D comprises a casing 65, consisting of a member integrally formedwith the head 63, a cover 66, and a rotor or impeller d for circulatingfluid through the cooling means of the engine fixed to the lower end ofshaft 63, which extends into casing 65. The casing has a depending inletduct 66 and outlet duct 61 for delivering cooling fluid to the engine,wherever desired. Since gear 62, which drives the impeller for thecooling fluid, is alternately driven by gears 33, 36, when the engine isrotating in opposite directions, the impeller will always be driven inthe same direction and function to deliver the cooling fluid to theengine. Shaft 63 is sealed'by packings 68, glands 69, and a spring 16interposed between the glands.

A gear H is formed on the hollow shaft 6| which is driven by theover-running or one-way clutch 62 and serves to drive the lubricant pumpG. Gear ll meshes with an idler gear I2 which is mounted on a stud 73which is carried by a head 9 which is removably secured to the bottom ofthe casing-extension 26, which contains an oil sump from which lubricantcan flow to pump G. Idler gear 12 meshes with a gear M which is fixed tothe'drive-shaft I5 of the pump G which is illustrated as the three-stagetype, each stage comprising a pair of intermeshing gears TI, 76. Two ofthe stages may be connected to scavenge the lubricating oil from thecrank-case and one may be used to supply lubricating oil under pressureto the lubricating system of the engine. The case g of pump G isremovably mounted on .the head 9 which is secured to thecasing-extension 26. Since the lubricating pump G is driven from beveledgear 42 through shafts 58, 6|, gears H, 12, 14, and gear 42 is driven inthe same direction while the engine is driven in either direction,through the selective adjustment of shaft 28, the gear-pump G will bedriven in the same direction at all times, to function with the enginewhile it is driven in either direction or with a right or a lefthandengine.

A hollow shaft III is journaled in a head ||2 which is removably securedin the housing-member 21 and carries at its inner end an integralbeveled gear 3 which meshes with a beveled gear 4 integral with theshaft 6| which is driven through the over-running spring clutch 62. Theouter end of shaft III is provided with a splined socket 5 to adapt itto receive the shaft of a small electric motor a: which is illustratedin Fig. 2 as detached from the assembly. The purpose of the over-runningclutch 62 and this shaft is to permit the impeller for the cooling fluidand the lubricant pumps, which are also driven by shaft 6| to beoperated independently of the engine and the other auxiliary equipment.

Starting the engine in cold weather is sometimes dimcult and, bysupplying pro-heated liquid to the cooling means for the engine fromimpeller D and pre-heated lubricant to the lubricant-circulating systemof the engine, the temperature of the working parts of the engine willbe increased and facilitate the starting of the engine.

When this is desired the shaft of a small portable electric motor (notshown), or a shaft from any other source of power, can be coupled to theouter end of shaft Hi to drive the shaft 6| through gears I I3, I I4 inthe direction for normal operation. The spring-clutch 62 will permit theshaft 6| to rotate in its designed direction while the shaft 58,. whichis normally driven from the engine, remains idle. This operation ofshaft I will operate the impeller D through shafts 6| and 63 and willoperate the lubricant pump G through gears H, 12, 14, In thisoperation,- any suitable means, such as an electric heater, may be usedto heat the lubricant in the pump to cause it to circulate heated oilthrough the lubricating system of the engine. This exemplifies means fordriving, from an outside source, for starting purposes, the impeller Dfor the coolant and the lubricant pump G, independently of the engineand the other auxiliary equipment driven by gears 33, 48 and 4!, whichare normally operated by the engine. By reason of the reversibility ofshaft 28, this mechanism is normally operable from a right or left-handengine.

The rotary pump B for forcing air to supercharge the motor comprises acasing b which is secured to the back of a housing-,member 21 which isfixed to the rear end of the crank-case extension 26, and a rotor orimpeller 8| with blades 82 for drawing air from a valve-controlledintake 83 and propelling it from the casing 1) into the manifold b whichdelivers the air to the intakes of the engine cylinders, as wellunderstood in the art. Rotor 8| is driven from beveled gear 33 sothat-it will always be driven in the same direction while thecrank-shaft of the motor is rotated in either direction.

The driving mechanism for the impeller B comprises a gear 85 which issplined to the hub of gear 33; a set. of three pinions 85 which meshwith gear 85; a set of three helical gears 93 mounted on shafts 81; ahydraulic drive H between each of the pinions 86 and gear 93: and ahelically toothed pinion 94 which meshes with the gears 93 and isintegrally formed with the shaft 95 to which the impeller 8| is splined.

Since the super-charger is driven from beveled gear 33 through thegearing last described, it will always be driven in the same directionwhile the engine is rotated in opposite direction.

A shaft I06, co-axial with the crank-shaft and shaft 28, is splined atNJ! to the shaft 3| of gear 33. This'shaft extends outwardly through thehollow shaft 95 which carries and drives the impeller head 8| and hasits outer end journaled in a bearing I08 carried by the casing I9 of thesuper-charger. The outer end of this shaft has a splined socket I09which is adapted to receive a shaft for any additional auxiliarymechanism desired. A cap H0 is secured to enclose the end of shaft I86when it is not in use.

In operation, the engine drives the entire auxiliary equipment throughshaft 28. If the engine is set to operate, or is operative in onedirection, the shaft 28 will be placed in the position to engage thegear 33 by means of splines 31. The entire auxiliary equipment will thenbe driven in the proper direction for which it is designed. When theengine is set so as to be, or is operated in the reverse direction, theshaft 28 will be reversed so that its spline 38 will drive the gear 36which, through gears 40, ll, 42, rotates in the opposite direction togear33. By connecting the shaft 28 to drive the oppositely rotating gear36, with the oppositely running crank-shaft, the entire auxiliaryequipment will function in its proper direction, notwithstanding thechange in direction of rotation of the engine.

When difiiculty is encountered in starting the engine, the pump D andlubricant pump G will be operated from an outside source through shaftHI, as hereinbefore described.

The invention exemplifies means whereby the impeller for coolant may bedriven from an outside source and independently of the crank-shaft andother auxiliary equipment, so that heated fluid can be circulated aroundthe engine to increase the temperature and aid combustion preparatory'to starting the engine. Also means whereby the lubricant pump may beoperated from an outside source of power, independently of thecrank-shaft, to circulate heated oil through the lubricating system ofthe engine to reduce friction of the working parts in starting theengine. Also, independently operable auxiliary equipment for thesepurposes which is adapted to be normally driven from an engine rotatingeither in a right or left-hand direction.

The invention is not to be understood as restricted to the details setforth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

- What I claim as new and desire to secure by Letters Patent is:

1. In an auxiliary assembly adapted for use with an engine, thecombination of a unidirectional rotary device for forcing afluid to theengine, a shaft adapted to be connected to and driven by the engine, anautomatically-acting one-way clutch comprising a clutch-spring and apair of coaxial shafts into both of which the spring is extended, one ofsaid hollow shafts being connected to be driven by the engine-drivenshaft and the other of which is connected to drive the device, atransversely extending shaft, gears betweenthe transversely extendingshaft and the hollow shaft connected to drive the device, and means forcoupling an auxiliary motor to the outer end of the transverselyextending shaft.

2. In an auxiliary assembly adapted for use with an engine, thecombination of a plurality of uni-directional rotary devices for forcingdifferent fluids to the engine, a shaft adapted to be connected to anddriven by the engine, an automatically-acting one-way clutch comprisinga clutch-spring and a pair of coaxial shafts into both of which thespring is extended, one of said hollow shafts being connected to bedriven by the engine-driven shaft and the other of which is connected todrive both of said devices, a transversely extending shaft, gearsbetween the transversely extending shaft and the hollow shaft connectedto drive the devices, and means for coupling an auxiliary motor to theouter end of the transversely extending shaft.

SAMUEL K. HOFFMAN.

